1. Field of Invention
This invention relates to producing bi-chromal balls for use in electric paper.
2. Description of Related Art
First and second color bi-chromal ball material with different electric and/or magnetic properties can be combined to form bi-chromal balls. FIG. 1 shows an exemplary bi-chromal ball 100 formed using a first color bi-chromal ball material 10 and a second color bi-chromal ball material 20. The exemplary bi-chromal ball 100 has a magnetic or electric dipole oriented top to bottom. Thus, the bi-chromal ball 100 shown in FIG. 1 will rotate when subjected to various magnetic or electric fields. The bi-chromal ball 100 can be produced using various admixtures and materials as known in the art.
The bi-chromal ball 100 can be used in electric paper. In electric paper, many bi-chromal balls are placed next to each other in a matrix to form a sheet. The bi-chromal balls can be rotated to form letters and pictures by alternating the showing of either the first color or second color sides.
As shown in FIG. 2, the bi-chromal balls 100 are conventionally formed using a known spinner 1000. The spinner 1000 has a bi-chromal ball material feeding portion 1220 and a spinning portion 1180. The bi-chromal ball material is fed in through material supply tubes 1110 and 1140 to a pair of reservoir portions 1130 and 1170. The bi-chromal balls 1190 are spun off of a disk 1200 of the spinning portion 1180. The bi-chromal ball material feeding portion 1220 does not spin and includes the material supply tubes 1110 and 1140 and one or more O-rings 1210. The O-rings 1210 are used to seal the ends of at least one of the material supply tubes 1110 and 1140.
The spinning portion 1180 includes first and second bi-chromal ball material transport portions 1120 and 1150 and a pair of bi-chromal ball material reservoirs 1130 and 1170. A first color bi-chromal ball material is fed through the material supply tube 1110, into the second bi-chromal ball material transport portion 1150, and flows through a third bi-chromal ball material transport portion 1160 into the bi-chromal ball material reservoir 1170. A second color bi-chromal ball material is fed through the material supply tube 1140, flows through the first bi-chromal ball material transport portion 1120 and into the bi-chromal ball material reservoir 1130. The bi-chromal ball material is then forced outward from the bi-chromal ball material reservoirs 1130 and 1170 by the pressure in the material supply tubes 1110 and 1140 and by the centrifugal force of the spinning disk 1200 and flows along the surfaces of the disk 1200 until it forms the bi-chromal balls 1190. The speed at which the bi-chromal ball material is fed to the disk 1200 to create the bi-chromal balls 1190 is controlled by the amount of pressure exerted on the bi-chromal ball material in the bi-chromal ball material supply tubes 1110 and 1140.
Inside of the spinning portion 1180, one color bi-chromal ball material is kept from the other color bi-chromal ball material in the bi-chromal ball material transport portions 1120 and 1150 by the one or more O-rings 1210, 1211, 1212 and 1213. The one or more O-rings 1210 form a seal between the non-spinning bi-chromal ball material feed portion 1220 and the spinning portion 1180, while the other O-rings are static and do not seal rotating parts.
U.S. Pat. Nos. 5,262,098 and 5,344,594, each incorporated herein by reference in its entirety, teach various methods for using liquids fed on opposite sides of a spinner to spread liquids.
This invention provides a bi-chromal ball production apparatus and method that is simpler to operate.
This invention separately provides a bi-chromal ball production apparatus and method that can operate at higher speeds.
This invention separately provides a bi-chromal ball production apparatus and method that has a greater control over the speed of the spinner.
This invention separately provides a bi-chromal ball production apparatus and method that has a higher yield of bi-chromal balls produced.
One or more of these various features and advantages of the invention are realized by feeding the bi-chromal ball material from opposite sides of the disk, reconfiguring the internal geometry of the apparatus and of controllably configuring the bi-chromal ball material feeding slit.
In various exemplary embodiments of the bi-chromal ball production apparatus according to this invention, the bi-chromal ball production apparatus has a disk that rotates, a first material supply tube that supplies a first bi-chromal ball material to a first side of the disk from a first direction, a second material supply tube that supplies a second bi-chromal ball material to a second side of the disk from a second direction, and a motor that rotates the disk. The bi-chromal ball production apparatus may include a first slit defined by the disk and a first housing and/or a second slit defined by the disk and a second housing. In various exemplary embodiments, the first and second slits each have a length of about 0.045 inches, a height of about 0.0025 inches and end at a distance of 0.775 inches from the center of rotation.
In various exemplary embodiments the apparatus may include a first reservoir portion defined by the disk, the first housing, the first slit and the first feed tube and a second reservoir portion defined by the disk, the second housing, the second slit and the second feed tube. In various exemplary embodiments, the disk may rotate at a speed of about 1800 revolutions per minute to about 5600 revolutions per minute.